Carbon dioxide systems, including apparatuses for creating solid carbon dioxide particles, for entraining particles in a transport gas and for directing entrained particles toward objects are well known, as are the various component parts associated therewith, such as nozzles, are shown in U.S. Pat. Nos. 4,744,181, 4,843,770, 5,018,667, 5,050,805, 5,071,289, 5,188,151, 5,249,426, 5,288,028, 5,301,509, 5,473,903, 5,520,572, 6,024,304, 6,042,458, 6,346,035, 6,695,679, 6,726,549, 6,739,529, 6,824,450, 7,112,120, 8,187,057 and 8,869,551, all of which are incorporated herein in their entirety by reference. Additionally, U.S. Patent Provisional Application Ser. No. 61/487,837 filed May 19, 2011 and U.S. non-Provisional Patent Application Ser. No. 13/475,454 filed May 18, 2012 both For Method And Apparatus For Forming Carbon Dioxide Particles, U.S. Patent Provisional Application Ser. No. 61/589,551 filed Jan. 23, 2012, for Method And Apparatus For Sizing Carbon Dioxide Particles, and U.S. Patent Provisional Application Ser. No. 61/592,313 filed Jan. 30, 2012, for Method And Apparatus For Dispensing Carbon Dioxide Particles, 14/062,118 filed Oct. 24, 2013 for Apparatus Including At Least An Impeller Or Diverter And For Dispensing Carbon Dioxide Particles And Method Of Use, all are hereby incorporated in their entirety by reference. Although this patent refers specifically to carbon dioxide in explaining the invention, the invention is not limited to carbon dioxide but rather may be applied to any suitable cryogenic material. Thus, references to carbon dioxide herein are not to be limited to carbon dioxide but are to be read to include any suitable cryogenic material.
Many prior art blasting system include rotating members, such as rotors, with cavities or pockets for transporting particles into the transport gas flow. Seals are used, urged against the rotor surface to maintain the pressure differential, with the goal of minimizing parasitic loses due to the contact while obtaining adequate sealing.